The ruling is the latest to shield the U.S. government's anti-terrorism surveillance programs from court challenge. Critics see a setback for privacy rights.

WASHINGTON — No one can sue the government over secret surveillance because, since it's secret, no one can prove his or her calls were intercepted, the Supreme Court ruled Tuesday, throwing out a constitutional challenge to the government's monitoring of international calls and emails.

The 5-4 decision is the latest of many that have shielded the government's anti-terrorism programs from court challenge, and a striking example of what civil libertarians call the Catch-22 rule that blocks challengers from collecting the evidence they need to proceed.

Over the last decade, the justices or lower court judges have repeatedly killed or quietly ended lawsuits that sought to expose or contest anti-terrorism programs, including secret wiretapping, roundups or arrests of immigrants from the Mideast and drone strikes that kill American citizens abroad.

The court's conservative majority believes that matters of national security and the fight against terrorism are properly decided by the president and Congress, not through lawsuits. They have erected procedural barriers to block such suits. The only exception has been lawsuits brought on behalf of the prisoners at Guantanamo Bay, which have won new appeal rights for inmates.

The intense wiretapping of international electronic traffic began shortly after the attacks of Sept. 11, 2001. President George W. Bush was determined to detect secret terrorist plots, if possible, and ordered the National Security Agency to intercept calls and messages coming into and out of the country. Bush chose to bypass a special court created to oversee "foreign intelligence surveillance."

When Bush's order was revealed, civil libertarians called the mass surveillance unconstitutional. But Congress, with the support of Democrats and Republicans, approved even broader electronic surveillance in 2008. By law, the targets of that surveillance must be outside the United States, but lawmakers acknowledged that calls and messages of some Americans would be inadvertently intercepted.

Amnesty International, Human Rights Watch and other groups began a new challenge, suing on behalf of lawyers, journalists and human rights advocates. They argued the expanded surveillance was unconstitutional because it would chill free speech and permit illegal searches of "purely domestic communications."

They won a preliminary victory when the U.S. 2nd Circuit Court of Appeals in New York said they had standing to sue. Because the plaintiffs had clients and contacts abroad, they had a "reasonable fear" their calls would be intercepted, the appeals court said.

The Obama administration appealed last year, and the Supreme Court tossed out the suit Tuesday in the case of Clapper vs. Amnesty International.

Justice Samuel A. Alito Jr. said the lawsuit was based on speculation, not evidence of how the program worked. The plaintiffs "have no actual knowledge of the government's targeted practices. Instead, [they] merely speculate and make assumptions," he said. Chief Justice John G. Roberts Jr. and Justices Antonin Scalia, Anthony M. Kennedy and Clarence Thomas joined his opinion.

Alito cited the Supreme Court's strict rules on standing, which hold that a case cannot go forward unless a complaining party can show he or she has suffered an "actual or imminent" injury. Alito said that this approach prevented judges from "usurping the powers of the political branches" of government.

In dissent, the court's four liberal justices said the lawsuit should have gone forward because the plaintiffs had to alter their work practices to avoid having their confidential calls overheard. "In my view, this harm is not 'speculative,'" Justice Stephen G. Breyer said.

The PEN American Center, which represents writers, called it a "Kafkaesque holding.... The U.S. government is running a secret program that monitors people. In order to challenge the legality of the program, the court's majority says you have to show that you're being monitored. You can't show this, of course, because the program is secret," said Peter Godwin, the group's president.

Jameel Jaffer, a lawyer for the American Civil Liberties Union, called the decision disturbing. It "insulates the statute from meaningful judicial review and leaves Americans' privacy rights to the mercy of the political branches."

But a lawyer for six former U.S. attorneys general applauded the decision. It "sends a clear message that politically motivated litigation over national security is untenable," said Megan L. Brown, a Washington attorney who represented them. The courts should not "second-guess" the president and Congress on "sensitive national issues," she said.